Temperature characteristics of noise figure of erbium-doped fiber amplifiers

Erbium-doped fiber amplifiers (EDFA's) are very attractive for optical-fiber telecommunications owing to their high gain and low noise.1 However, for practical use the stabilities of the gain and noise of the EDFA are important issues. Recently the temperature dependence of the gain in an EDFA has been reported.2 This paper describes the temperature dependence of noise figure (NF) for three types of EDFA. The experimental results show that NF variation from changes in temperature can be reduced by aluminum codoping.